Adding Durability to my Gear Spreadsheet?

All of this talk about weighing gear and recording this on spreadsheets has started me thinking.

I am considering adding a record of durability to the sheet and am wondering whether anyone has done this before. This would have to be done using some macro of clever table calculations but basically it would work like this.

Each time that I went out for a trip I would input the number of days or nights (or days and nights) of the trip. The macro would them add the number of days to a count in a master list. I could do this automatically using one input field or — probably more accurately — could just add it to those items who’s lifespan I was measuring.

So, if I bought a new sleeping mat I could keep an absolute record of the number of nights that I slept on it. Of course, this would still not reflect ground conditions and so on but basically I think this would give me an interesting record.

There are other items that I wonder about. For example, I like using merino boxers but find that these do tend to fall to bits after a while. It would be nice to know exactly how long they last though. The lifespan of different sets of the same item could be averaged over time.

I know, I know, it is time to go back to work. But if those of us who kept spreadsheet tables all did something similar then we would quickly build up an interesting record of durability. I’ll have a crack at something over the next few days.